Tank manufacturer and thread size?

[Ghost95]

Good morning all. I was just informed about some old steel tanks a neighbor is getting rid of and I had a couple questions.

The tank has a first hydro of 1962. That's neat because they're in good condition. They are both Sportsways tanks. 72's I think. I'm not home to see them though so all this is email from the wife.

Anyway there is a manufacturing code that begins with HJ ######. At least I think that's what it is.

I was wondering if that would allow someone to tell me these were the 1/2" thread tanks or the 3/4".

I know Sportsways had that weird 1/2" straight thread that is pretty rare and might be a problem to work on our replace. But they also have 3/4" valves and tanks too. I'd like to be able to just swap valves to something newer if possible.

Anyway, is the HJ a manufacturing code that I could use to see what the neck threads are? Or, does anyone know what the threads are for a steel 72 (I think) from Sportsways in 1962.

Again, I'm not home where the tanks are so I can't put my grubby little hands on them to see what they are.

Thanks for any help.

 

[tbone1004]

please post some pictures. If you can post the valve markings there will be a manufacturer code on there and we can see from the valve what thread it is

 

[rhwestfall]

subscribing.... I am in a similar situation, and getting more information shortly.

I hope this isn't taken as a hijack....

 

[Scared Silly]

The easiest is to just look at the valve that is currently on each cyclinder. If while installed you see threads, then it is 1/2 tapered, no threads visible then straight threads, If the latter, then pull the valve and measure. Given the age, I would be betting 1/2 tapered threads.

 

[Ghost95]

Thanks for the reply guys. I'm in Guyana for a few more days then I'll get to see the tanks.

WidW didn't get pictures so I'll just have to wait till I get home.

I looked up Sportsways valves and in 1962 they made "K" valves in both 3/4" and 1/2". Their catalog for that year didn't show any tapered NPT tapered threaded valves.

I'll give it a look see when I get home and who knows. I might dive a 72 again.

 

[Akimbo]

There is some information on the history of threads used in the US in this thread: Scuba Cylinder Valve Installation

 

[2airishuman]

Good morning all. I was just informed about some old steel tanks a neighbor is getting rid of and I had a couple questions.

The tank has a first hydro of 1962. That's neat because they're in good condition. They are both Sportsways tanks. 72's I think. I'm not home to see them though so all this is email from the wife.

Anyway there is a manufacturing code that begins with HJ ######. At least I think that's what it is.

Those would be Norris cylinders.

I was wondering if that would allow someone to tell me these were the 1/2" thread tanks or the 3/4".

I know Sportsways had that weird 1/2" straight thread that is pretty rare and might be a problem to work on our replace. But they also have 3/4" valves and tanks too. I'd like to be able to just swap valves to something newer if possible.

Anyway, is the HJ a manufacturing code that I could use to see what the neck threads are? Or, does anyone know what the threads are for a steel 72 (I think) from Sportsways in 1962.

I believe that Norris made cylinders with all the thread styles you mention. I know I've seen PST cylinders with all three threads. There is no difference in the markings. The "weird 1/2" straight thread" may be M18. Most days there are M18 Scuba valves on eBay, and right now there are some nice provalve din/yoke ones with burst discs.

Diving 4500psi Carbon Fiber Scuba Tank Valve Gas Cylinder Thread M18*1.5 | eBay

1/2" npt (tapered) valves are available from the usual sources. They are somewhat more of a nuisance to remove and install.

XS Scuba Pro Valve with 1/2

You will want to consider the cost of hydro, tumbling, the new valve, and blast/paint if needed. I have several myself, and they can be a good deal.

Some cylinders from this era have liners that should be tumbled out so that any corrosion behind the liner becomes visible and can be evaluated.

 

[2airishuman]

A fact to consider since you're in Florida is that some people have reported difficulty getting fills on LP72s due to (misguided) dive shop policies on maximum cylinder age.

 

[Ghost95]

I asked the wife if she could see threads on the valve coming out of the tank and she said she didn't think so. That would at least eliminate the tapered NPT. Could still be either half ou theth quarter.